Method and device for lubricant oil transport in an internal combustion engine

ABSTRACT

A lubricant oil transport device and method is provided in an internal combustion engine using wet sump lubrication. Near the connecting rod and the crankshaft cheeks, which are disposed exteriorly in the transverse acceleration and/or inclination direction and lie opposite a decentralized oil suction system, the oil repulsion part is configured to cause a centrifugal flow for oil transport in the oil pan area opposite the transverse acceleration and/or inclination, resulting from interaction of the oil repulsion part, connecting rod, and crankshaft cheeks. Thus, lubricant oil supply is always assured, without pumps additionally integrated into the engine, which increase costs and likelihood of failure. The oil pan may also now be flatter, which allows a low center of gravity of the engine while maintaining the required minimum road surface distance. Regarding oil change intervals, a greater amount of oil can be used, with the same proportions of the oil pan.

BACKGROUND OF THE INVENTION CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of German Application No. 10 2004 024 780.3 filed May 17, 2004.

1. Field of the Invention

The present invention relates to a method and a device for lubricant oil transport in an internal combustion engine using wet sump lubrication.

2. The Prior Art

It is known that in the case of transverse installation into a motor vehicle of an internal combustion engine using wet sump lubrication, the lubricant oil supply is problematic when severe transverse acceleration, inclination, or both occurs. The central suction system is disposed deep in the wet sump and is connected with the lubricant pump. Thus, a risk exists that the central suction system will draw air in, instead of lubricant oil, and thereby interrupt lubricant circulation.

To improve the reliability of the lubricant oil supply in case of severe transverse acceleration and/or inclination of an internal combustion engine, a separation of the oil pan into two segments is proposed in DE 101 19 924 A1. The first segment is connected with a wet sump circulation system, and the second segment is connected with a dry sump circulation system. Consequently, the oil pan is made to be more compact in the region of the wet sump. The height/width ratio of the oil pan increases, and allows reliable suctioning of lubricant oil from the wet sump even in case of severe transverse acceleration and/or inclination.

In this embodiment, several lubricant pumps are necessary. One lubricant pump draws lubricant oil off from the wet sump and passes it into the lubricant circulation. Another lubricant oil pump draws lubricant oil off from the dry sump and passes it into a cyclone. Pumps that are additionally integrated into an internal combustion engine are cost-intensive and increase the failure probability of the internal combustion engine.

Furthermore, the use of splash baffles or partition elements to suppress excessive lubricant oil movements is known from DE 196 20 905 A1. The splash baffles or partition elements divide the space in the oil pan into several chambers that are connected with one another.

In severe transverse acceleration and/or inclination conditions, such partition elements can prevent air from being drawn in from the wet sump by way of the central suction system. This prevention, however, lasts only for a short period of time, as a result of the delayed equalization of the lubricant oil between the individual chambers.

An internal combustion engine having a cylindrical crankcase, at least in some areas, is known from DE 90 07 511 U1. With this arrangement, a centrifugal flow occurs as a result of the parts rotating in the crankcase. This centrifugal flow is used to handle the lubricant oil. An outflow bore that opens tangentially into the crankcase is also provided to remove the lubricant oil.

The lubricant oil supply of an internal combustion engine solely on the basis of this transport possibility must be assessed critically. Uniform lubricant oil transport in all the inclination states of the internal combustion engine cannot be expected, because not all the rotating parts are in contact with the lubricant oil at the same time.

It is furthermore possible to provide deeper oil pans to improve the reliability of the lubricant oil supply in case of severe transverse acceleration and/or inclination of an internal combustion engine. The height/width ratio of the oil pan increases, and allows reliable suctioning of lubricant oil from the wet sump even in case of severe transverse acceleration and/or inclination.

However, this possibility requires an undesirable elevation of the center of gravity of the internal combustion engine, due to the required minimum distance of the oil pan from the road surface.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a device and a method that assure the availability of the lubricant oil supply of an internal combustion engine using a wet sump and installed transversally in the simplest possible manner and without additional moving components, in the case of severe transverse acceleration and/or inclination. In addition, it is an object of the present invention to provide a device and a method which maintains both the required minimum distance of the oil pan from the road surface and a low center of gravity of the internal combustion engine.

These and other objects are achieved, according to one aspect of the invention, by a device for lubricant oil transport in an internal combustion engine using wet sump lubrication, having a lubricant oil pump, a lubricant oil suction system; a crank mechanism made from connecting rods and crankshaft cheeks, an oil pan having splash baffles or partition elements, and an oil repulsion part.

The oil repulsion part is configured, in the region of the connecting rod and the crankshaft cheeks, which are disposed lying on the outside in the direction of the transverse acceleration, inclination, or both, so that the running paths of the connecting rod and the crankshaft cheeks pass along the oil repulsion part at a slight distance from it.

The oil repulsion part has one or more tangentially disposed lubricant oil outflow openings in the region of the connecting rod and the crankshaft cheeks.

These lubricant oil openings are connected with a guidance system, which opens into the region of the oil pan opposite the transverse acceleration and/or inclination, in which the lubricant oil suction system is disposed.

In another embodiment, the connecting rod and the crankshaft cheeks are disposed lying on the outside in and opposite the direction of the transverse acceleration and/or inclination. The lubricant oil openings are connected with guidance systems, which open into the region of the oil pan directed in and opposite the transverse acceleration and/or inclination, whereby the lubricant oil suction system is disposed centrally in the oil pan.

In either embodiment, the oil pan may be provided with vertical partition elements. The guidance system passes through or circumvents the partition elements to transport the lubricant oil.

In a further aspect, a method is provided for transporting lubricant oil in an internal combustion engine using wet sump lubrication, having a lubricant oil pump for lubricant supply, a lubricant oil suction system for drawing the lubricant oil off from the oil pan, a crank mechanism made from connecting rods and crankshaft cheeks, an oil pan having splash baffles or partition elements, and an oil repulsion part.

In accordance with the method, when the lubricant oil surface rises above the oil repulsion part, as a result of severe transverse acceleration, inclination, or both, in the region of the connecting rod and the crankshaft cheeks, which are disposed on the outside in the direction of the transverse acceleration and/or inclination, and lie opposite a lubricant oil suction system disposed in the region of the oil pan that lies opposite the transverse acceleration and/or inclination, a contact of the connecting rod and the crankshaft cheeks with the lubricant oil surface is formed. Because of this contact, in interaction with the correspondingly configured oil repulsion part, lubricant oil transport into the region of the oil pan that lies opposite the transverse acceleration and/or inclination, in which the lubricant suction system is disposed, is achieved by way of the lubricant oil outflow openings tangentially disposed in the oil repulsion part, and the guidance system.

In another embodiment of the method, the connecting rod and the crankshaft cheeks are disposed on the outside in or opposite the direction of the transverse acceleration and/or inclination, and between which a lubricant oil suction system is centrally disposed in the oil pan. When the lubricant oil surface rises above the oil repulsion part, as a result of severe transverse acceleration and/or inclination in the region of the connecting rod and the crankshaft cheeks, a contact of the connecting rod disposed on the outside, in or opposite the direction of the transverse acceleration and/or inclination, and the crankshaft cheeks with the lubricant oil surface, is formed.

According to the invention, the characteristics described below are taken into consideration for an internal combustion engine using wet sump lubrication and having a lubricant oil pump. The connecting rod and the crankshaft cheeks are disposed on the outside in the direction of the transverse acceleration and/or inclination and lie opposite a decentrally disposed lubricant oil suction system. The oil repulsion part that is integrated into the internal combustion engine is configured, in the region of the connecting rod and the crankshaft cheeks, so that a centrifugal flow is achieved in the region of the oil pan that lies opposite the transverse acceleration and/or inclination, resulting from the interaction of oil repulsion part, the connecting rod, and the crankshaft cheeks.

This arrangement has the advantage that the lubricant oil supply of a transversally installed internal combustion engine using wet sump lubrication is assured in the case of severe transverse acceleration and/or inclination, without pumps additionally integrated into the internal combustion engine, which increase the costs and the failure likelihood of the internal combustion engine. Furthermore, the oil pan can be designed to have a flat construction, which allows a low center of gravity of the internal combustion engine while maintaining the required minimum distance of the oil pan from the road surface. With regard to the lubricant oil change intervals, it is furthermore advantageous that a higher lubricant oil level and therefore a greater amount of lubricant oil can be used, while maintaining the proportions of the oil pan. These features are possible because the lubricant oil, in which air is entrained due to the contact of the crank mechanism with the lubricant oil, is transported into an oil pan area where no contact of the crank mechanism with lubricant occurs. In this area of the oil pan, the oil can separate from the entrained air.

Additional advantageous embodiments are described below; they will be explained together with their effects.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows the interaction of oil repulsion part 1 and connecting rod 2 for lubricant oil transport;

FIG. 2 is a basic representation of the lubricant oil transport according to an embodiment of the invention, with a decentralized lubricant oil suction system 11,

FIG. 3 is a basic representation of the lubricant oil transport according to another embodiment of the invention, with a central lubricant oil suction system 11, and

FIG. 4 is a view from below of oil repulsion part 1 with an expanded guidance system 9.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings, FIG. 2 shows an oil repulsion part 1 integrated into an internal combustion engine 3. A connecting rod 2 and crankshaft cheeks 4 are disposed on the outside in the direction of the transverse acceleration and/or inclination R. The direction of the transverse acceleration relating to the present invention means the direction of the centrifugal acceleration which is directed against the centripetal acceleration. Oil repulsion part 1 is configured, in the region of connecting rod 2 and crankshaft cheeks 4 so that a centrifugal flow, resulting from the interaction of oil repulsion part 1, connecting rod 2, and crankshaft cheeks 4 is brought about. This centrifugal flow is used for transport of the lubricant oil into the region of an oil pan 6 that lies opposite the transverse acceleration and/or inclination. A lubricant oil suction system 11 is disposed in this region of oil pan 6.

An oil repulsion part 1 of the type shown in FIGS. 1 to 4, in an internal combustion engine 3 using wet sump lubrication, is a known means for reducing the air content in the lubricant oil that is drawn in. With this component, which uncouples the crank mechanism 5 and oil pan 6 spatially from one another, it is possible to avoid contact of connecting rods 2 and crankshaft cheeks 4 with the lubricant oil surface 7, in normal operation of an internal combustion engine 3 using wet sump lubrication, without severe transverse acceleration and/or inclination.

As shown in FIG. 1, oil repulsion part 1 is configured, in the region of connecting rod 2 and crankshaft cheeks 4, which are disposed on the outside in the direction of the transverse acceleration and/or inclination R, so that the running paths of connecting rod 2 and crankshaft cheeks 4 pass along oil repulsion part 1 at a slight distance from it. Oil repulsion part 1 according to the invention has one or more tangentially disposed lubricant oil outflow openings 8, in the region of connecting rod 2 and crankshaft cheeks 4. Openings 8 are disposed on the outside in the direction of the transverse acceleration and/or inclination R, in accordance with the direction of rotation of crank mechanism 5, and are connected with a guidance system 9 for transporting the lubricant oil.

As a result of severe transverse acceleration and/or inclination, the lubricant oil surface 7 rises above oil repulsion part 1 in the region of connecting rod 2 and crankshaft cheeks 4, which are disposed on the outside in the direction of the transverse acceleration and/or inclination R, and lie opposite a decentrally disposed lubricant oil suction system 11. A contact of connecting rod 2 and crankshaft cheeks 4 with lubricant oil surface 7 comes about. The contact of connecting rod 2 and crankshaft cheeks 4 with lubricant oil surface 7 interacts with the correspondingly configured oil repulsion part 1. As a result, lubricant oil is transported into the area of oil pan 6 that lies opposite the transverse acceleration and/or inclination, in which the lubricant oil suction system 11 is disposed.

The oil transport effect results from the centrifugal forces that become active as a result of connecting rods 2 and crankshaft cheeks 4 that lie on the outside, in each instance, in contact with lubricant oil surface 7, which forces bring about a flow and a pressure increase in the lubricant oil. Because of the tangential arrangement of lubricant oil outflow openings 8 that are located in oil repulsion part 1, a flow is achieved in guidance system 9 for lubricant oil transport.

As is shown in FIGS. 1 to 4, a simple guidance system 9 that opens into the region of oil pan 6 opposite the transverse acceleration and/or inclination, is provided for lubricant oil transport from the region of connecting rods 2 and crankshaft cheeks 4, which lie on the outside, in each instance.

In another advantageous embodiment in accordance with FIG. 2, oil pan 6 is provided with vertical partition elements 10. Vertical partition elements 10 delay the return flow of the lubricant oil in the direction of the transverse acceleration and/or inclination R. Guidance system 9 for lubricant oil transport passes through or circumvents vertical partition elements 10 disposed in oil pan 6, depending on the design situation, in each instance.

In the case of a severe transverse acceleration and/or inclination in the direction of the region of oil pan 6 in which lubricant oil suction system 11 is disposed, no lubricant oil transport takes place. The lubricant oil is reliably drawn in by way of lubricant oil suction system 11. The risk is therefore slight that air will be drawn in, instead of lubricant oil, by way of the decentrally disposed lubricant oil suction system 11 connected with the lubricant pump. Therefore, the risk is likewise slight that lubricant circulation will be interrupted.

Alternatively, as shown in FIG. 3, a reliable lubricant oil supply is possible also with a central arrangement of lubricant oil suction system 11. For this purpose, the configuration of oil repulsion part 1 should be structured, also in the region of connecting rod 2 and crankshaft cheeks 4, which are disposed on the outside opposite the direction of the transverse acceleration and/or inclination R, so that the running paths of connecting rod 2 and crankshaft cheeks 4 pass along oil repulsion part 1 at a slight distance from it. Oil repulsion part 1 then has one or more tangentially disposed lubricant oil outflow openings 8 also in the area of connecting rod 2 and crankshaft cheeks 4. Openings 8 are disposed on the outside opposite the direction of the transverse acceleration and/or inclination R, in accordance with the direction of rotation of crank mechanism 5 and are connected with another guidance system 9 for lubricant oil transport. Guidance system 9 must be expanded for this embodiment, in accordance with the view shown in FIG. 4.

In this manner, lubricant oil transport depending on the direction of the transverse acceleration and/or inclination is achieved, and the risk that air will be drawn in, instead of lubricant oil, by way of the centrally disposed lubricant oil suction system 11 connected with the lubricant pump, and that the lubricant circulation will therefore be interrupted, is therefore slight.

Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims. 

1. A device for lubricant oil transport in an internal combustion engine using wet sump lubrication and having a transverse acceleration or inclination with a direction comprising: (a) a lubricant oil pump, (b) a lubricant oil suction system; (c) a crank mechanism comprising a plurality of connecting rods and associated crankshaft cheeks having running paths; (d) an oil pan comprising a plurality of separators; (e) an oil repulsion part; (f) a guidance system opening into an area of said oil pan opposite said transverse acceleration or inclination where said lubricant oil suction system is disposed; wherein said connecting rods and said crankshaft cheeks are disposed exteriorly of said oil repulsion part in the direction of the transverse acceleration or inclination, said oil repulsion part being arranged near said connecting rods and said crankshaft cheeks so that the running paths of each connecting rod and associated crankshaft cheeks pass along near said oil repulsion part; wherein said oil repulsion part has at least one tangentially disposed lubricant oil outflow opening near each connecting rod and associated crankshaft cheeks; and wherein said at least one lubricant oil outflow opening is connected to said guidance system.
 2. The device according to claim 1, wherein said separators are selected from the group consisting of splash baffles and partition elements.
 3. The device according to claim 1, wherein said separators comprise vertical partition elements and said guidance system passes through or around said partition elements for transport of lubricant oil.
 4. A device for lubricant oil transport in an internal combustion engine using wet sump lubrication and having a transverse acceleration or inclination comprising: (a) a lubricant oil pump, (b) a lubricant oil suction system; (c) a crank mechanism comprising a plurality of connecting rods and associated crankshaft cheeks having running paths; (d) an oil pan comprising a plurality of separators, said lubricant oil suction system being disposed centrally in said oil pan; (e) an oil repulsion part; and (f) a plurality of guidance systems opening into an area of said oil pan toward and opposite said transverse acceleration or inclination; wherein said connecting rods and said crankshaft cheeks are disposed exteriorly of said oil repulsion part in and opposite the direction of the transverse acceleration or inclination, said oil repulsion part being arranged near said connecting rods and said crankshaft cheeks so that the running paths of each connecting rod and associated crankshaft cheeks pass along near said oil repulsion part; wherein said oil repulsion part has at least one tangentially disposed lubricant oil outflow opening near each connecting rod and associated crankshaft cheeks; and wherein said at least one lubricant oil outflow opening is connected into an area of the oil pan in and opposite the direction of the transverse acceleration or inclination.
 5. The device according to claim 4, wherein said separators are selected from the group consisting of splash baffles and partition elements.
 6. The device according to claim 4, wherein said separators comprise vertical partition elements and said guidance system passes through or around said partition elements for transport of lubricant oil.
 7. A method for transporting lubricant oil in an internal combustion engine using wet sump lubrication and having a lubricant oil pump for lubricant supply, an oil pan having a plurality of separators, a lubricant oil suction system for drawing the lubricant oil off from the oil pan, a crank mechanism comprising a plurality of connecting rods and associated crankshaft cheeks, an oil repulsion part, and a transverse acceleration or inclination with a direction comprising the steps of: (a) disposing the lubricant oil suction system in an area of the oil pan that lies opposite the transverse acceleration or inclination; (b) disposing each connecting rod and associated crankshaft cheeks exteriorly of the oil repulsion part in the direction of the transverse acceleration or inclination and arranging each connecting rod and associated crankshaft cheeks to lie opposite the lubricant oil suction system so that the connecting rod and associated crankshaft cheeks form a contact with a lubricant oil surface when severe transverse acceleration or inclination near the connecting rod and associated crankshaft cheeks causes the lubricant oil surface to rise above the oil repulsion part; and (c) transporting lubricant oil into the area of the oil pan that lies opposite the transverse acceleration or inclination as a result of the contact in interaction with the oil repulsion part by way of lubricant oil outflow openings tangentially disposed in the oil repulsion part and a guidance system.
 8. The method according to claim 7 wherein the separators are selected from the group consisting of splash baffles and partition elements.
 9. A method for transporting oil in an internal combustion engine using wet sump lubrication and having a lubricant oil pump for lubricant supply, an oil pan having a plurality of separators, a lubricant oil suction system for drawing lubricant oil from the oil pan, a crank mechanism comprising a plurality of connecting rods and associated crankshaft cheeks, an oil repulsion part, and a transverse acceleration or inclination with a direction comprising the steps of: (a) disposing the lubricant oil suction system centrally in the oil pan relative to the connecting rods and crankshaft cheeks; (b) disposing each connecting rod and associated crankshaft cheeks exteriorly of the oil repulsion part in or opposite the direction of the transverse acceleration or inclination, so that the connecting rod and associated crankshaft cheeks form a contact with a lubricant oil surface when severe transverse acceleration or inclination near the connecting rod and associated crankshaft cheeks causes the lubricant oil surface to rise above the oil repulsion part; and (c) transporting lubricant oil into the area of the oil pan that lies opposite the transverse acceleration or inclination as a result of the contact in interaction with the oil repulsion part by a way of lubricant oil outflow openings tangentially disposed in the oil repulsion part and a guidance system.
 10. the method according to claim 9 wherein the separators are selected from the group consisting of splash baffles and partition elements. 